2,102 research outputs found
Variability in ostracod communities (Crustacea, Ostracoda) in connected and isolated tropical floodplain lakes
Floodplains mostly consist of primary and secondary riverbeds, connecting channels and lakes that are either isolated from rivers and channels for most of the year, or lakes that are connected to rivers and channels for most (or all) of the year. We hypothesize that the differences in invertebrate communities, as calculated by beta-diversities, will be higher in isolated than in connected lakes. We use ostracod communities in the pleuston of the floating macrophyte Eichhornia crassipes in the Upper Parana River floodplain to test this hypothesis. We have observed significant differences in species composition between the two types of lakes. However, although beta diversity values are indeed slightly higher in isolated than in connected lakes, these differences are not significant. This lack of clear effect of isolation on beta diversity could be owing to the fact that the period of isolation since the last homogenizing flood pulse had not been long enough, or because differences in degree of isolation become altogether insignificant in periods of low water flow
Relationship between Entrepreneurial Orientation and Project Management Maturity in Brazilian Software Firms
This paper aims to analyze the relationship between entrepreneurial orientation and project management maturity in software firms. Initially, the literature concerning both matters has been approached. Then, a conceptual model which suggests that the entrepreneurial orientation is positively related to the project management maturity, has been proposed. In order to evaluate this model, the Structural Equation Modeling technique has been adopted through the Partial Least Square method using a sample of 102 questionnaires given by managers of Brazilian software firms. The model was validated and the study hypothesis confirmed. The results of the study reveal that there is a positive relationship between entrepreneurial orientation and project management maturity in the surveyed firms. Thus, innovativeness, risk-taking and proactiveness exert a positive impact on the project management maturity, which is characterized by integration management, scope management, time management, cost management, quality management, human resources management, communications management, risk management and procurement management. The results collaborate with the theoretical discussions surrounding these subjects contributing to seal literature gap to combine entrepreneurship and project management. As managerial contributions, the study provides executives and managers to have a general view that the entrepreneurial orientation exerts beneficial impacts on the project management maturity
Reducing the power consumption in LTE-advanced wireless access networks by a capacity based deployment tool
As both the bit rate required by applications on mobile devices and the number of those mobile devices are steadily growing, wireless access networks need to be expanded. As wireless networks also consume a lot of energy, it is important to develop energy-efficient wireless access networks in the near future. In this study, a capacity-based deployment tool for the design of energy-efficient wireless access networks is proposed. Capacity-based means that the network responds to the instantaneous bit rate requirements of the users active in the selected area. To the best of our knowledge, such a deployment tool for energy-efficient wireless access networks has never been presented before. This deployment tool is applied to a realistic case in Ghent, Belgium, to investigate three main functionalities incorporated in LTE-Advanced: carrier aggregation, heterogeneous deployments, and Multiple-Input Multiple-Output (MIMO). The results show that it is recommended to introduce femtocell base stations, supporting both MIMO and carrier aggregation, into the network (heterogeneous deployment) to reduce the network's power consumption. For the selected area and the assumptions made, this results in a power consumption reduction up to 70%. Introducing femtocell base stations without MIMO and carrier aggregation can already result in a significant power consumption reduction of 38%
Mixed Matrix Carbon Molecular Sieve and Alumina (CMS-Al₂O₃) Membranes
This work shows mixed matrix inorganic membranes prepared by the vacuum-assisted impregnation method, where phenolic resin precursors filled the pore of a-alumina substrates. Upon carbonisation, the phenolic resin decomposed into several fragments derived from the backbone of the resin matrix. The final stages of decomposition (>650 degrees C) led to a formation of carbon molecular sieve (CMS) structures, reaching the lowest average pore sizes of similar to 5 angstrom at carbonisation temperatures of 700 degrees C. The combination of vacuum-assisted impregnation and carbonisation led to the formation of mixed matrix of CMS and a-alumina particles (CMS-Al2O3) in a single membrane. These membranes were tested for pervaporative desalination and gave very high water fluxes of up to 25 kg m(-2) h(-1) for seawater (NaCl 3.5 wt%) at 75 degrees C. Salt rejection was also very high varying between 93-99% depending on temperature and feed salt concentration. Interestingly, the water fluxes remained almost constant and were not affected as feed salt concentration increased from 0.3, 1 and 3.5 wt%
Relationship between Entrepreneurial Orientation and Project Management Maturity in Brazilian Software Firms
<p>This paper aims to analyze the relationship between entrepreneurial orientation and project management maturity in software firms. Initially, the literature concerning both matters has been approached. Then, a conceptual model which suggests that the entrepreneurial orientation is positively related to the project management maturity, has been proposed. In order to evaluate this model, the Structural Equation Modeling technique has been adopted through the Partial Least Square method using a sample of 102 questionnaires given by managers of Brazilian software firms. The model was validated and the study hypothesis confirmed. The results of the study reveal that there is a positive relationship between entrepreneurial orientation and project management maturity in the surveyed firms. Thus, innovativeness, risk-taking and proactiveness exert a positive impact on the project management maturity, which is characterized by integration management, scope management, time management, cost management, quality management, human resources management, communications management, risk management and procurement management. The results collaborate with the theoretical discussions surrounding these subjects contributing to seal literature gap to combine entrepreneurship and project management. As managerial contributions, the study provides executives and managers to have a general view that the entrepreneurial orientation exerts beneficial impacts on the project management maturity.</p
On Non-Abelian Symplectic Cutting
We discuss symplectic cutting for Hamiltonian actions of non-Abelian compact
groups. By using a degeneration based on the Vinberg monoid we give, in good
cases, a global quotient description of a surgery construction introduced by
Woodward and Meinrenken, and show it can be interpreted in algebro-geometric
terms. A key ingredient is the `universal cut' of the cotangent bundle of the
group itself, which is identified with a moduli space of framed bundles on
chains of projective lines recently introduced by the authors.Comment: Various edits made, to appear in Transformation Groups. 28 pages, 8
figure
Relationship between Entrepreneurial Orientation and Project Management Maturity in Brazilian Software Firms
This paper aims to analyze the relationship between entrepreneurial orientation and project management maturity in software firms. Initially, the literature concerning both matters has been approached. Then, a conceptual model which suggests that the entrepreneurial orientation is positively related to the project management maturity, has been proposed. In order to evaluate this model, the Structural Equation Modeling technique has been adopted through the Partial Least Square method using a sample of 102 questionnaires given by managers of Brazilian software firms. The model was validated and the study hypothesis confirmed. The results of the study reveal that there is a positive relationship between entrepreneurial orientation and project management maturity in the surveyed firms. Thus, innovativeness, risk-taking and proactiveness exert a positive impact on the project management maturity, which is characterized by integration management, scope management, time management, cost management, quality management, human resources management, communications management, risk management and procurement management. The results collaborate with the theoretical discussions surrounding these subjects contributing to seal literature gap to combine entrepreneurship and project management. As managerial contributions, the study provides executives and managers to have a general view that the entrepreneurial orientation exerts beneficial impacts on the project management maturity
Restricted Attentional Capacity within but Not between Sensory Modalities: An Individual Differences Approach
Background Most people show a remarkable deficit to report the second of two targets when presented in close temporal succession, reflecting an attentional blink (AB). An aspect of the AB that is often ignored is that there are large individual differences in the magnitude of the effect. Here we exploit these individual differences to address a long-standing question: does attention to a visual target come at a cost for attention to an auditory target (and vice versa)? More specifically, the goal of the current study was to investigate a) whether individuals with a large within-modality AB also show a large cross-modal AB, and b) whether individual differences in AB magnitude within different modalities correlate or are completely separate. Methodology/Principal Findings While minimizing differential task difficulty and chances for a task-switch to occur, a significant AB was observed when targets were both presented within the auditory or visual modality, and a positive correlation was found between individual within-modality AB magnitudes. However, neither a cross-modal AB nor a correlation between cross-modal and within-modality AB magnitudes was found. Conclusion/Significance The results provide strong evidence that a major source of attentional restriction must lie in modality-specific sensory systems rather than a central amodal system, effectively settling a long-standing debate. Individuals with a large within-modality AB may be especially committed or focused in their processing of the first target, and to some extent that tendency to focus could cross modalities, reflected in the within-modality correlation. However, what they are focusing (resource allocation, blocking of processing) is strictly within-modality as it only affects the second target on within-modality trials. The findings show that individual differences in AB magnitude can provide important information about the modular structure of human cognition
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